Consistency is key on the grass of SW19

Day 13 of The Championships saw Roger Federer lift the Wimbledon men’s singles title for a record eighth time. A remarkable run since 2003, that has also seen him finish as runner up on three occasions. Eleven final appearances in 15 years is incredible consistency, even for a player generally regarded as the best to ever pick up a racquet.

Like other great champions before him, such as Pete Sampras, Boris Becker and Bjorn Borg, he calls Centre Court ‘home’. This feeling comes from these players having a fantastic winning record, but also the knowledge that the playing surface is as consistent as their first serves.

Wimbledon ground staff toil for 365 days a year to ensure that playing surfaces on the courts are consistent from one year to the next. So that players can experience the same level of playing quality year after year.

New products, technologies and techniques are continually introduced to court preparation at The All England Club. However, basic grass court management remains consistent.

Centre Court and Court 1 are taken out of play at the end of The Championships. They are only ever used for The Championships, players must earn the right to play on these prestigious courts. Re-surfacing on these courts begins immediately after The Championships, to ensure they are ready for the following years event. Other Championship Courts are played on by members for the rest of the summer and renovated at the end of the season.

STRI work closely with The All England Club to ensure the grass is consistent from one year to the next.

As each Championships approach and preparations are ‘fine-tuned’, STRI begin to take measurements designed to measure surface characteristics on courts. These measurements are taken daily throughout the final preparation week and during The Championships.

Measurements taken prior to the start of The Championships are important because this is the opportunity to make any necessary adjustments. Courts can be irrigated or dried down to ensure that they are firm enough for play at the start of the event, but not too firm that surface characteristics will deteriorate later in the tournament.

Effectively, the Wimbledon ground staff manage and STRI measure, the relationship between the grass plant, soil and water on courts. Measurements taken include; surface hardness, volumetric moisture content, relative ball rebound, and live grass cover. The key measurement is surface hardness, measured with a Clegg impact soil tester. Surface hardness levels need to be approximately 200 gravities on day one of The Championships and a controlled increase to approximately 250 gravities by day 13 is desirable.

Measurements taken in 2017 are consistent with those measured in recent years. A good example of this is surface hardness on Centre Court. On day 13 in 2017 it measured 254 gravities, it was 241 gravities in 2016, 247 gravities in 2015, 249 gravities in 2014 and 261 gravities in 2013. A very tight range of 20 gravities. This is typical of the level of control achieved on all courts each year.

Consistency of surface characteristics and playing quality would be easy to achieve but for one variable. The British weather!

Surface characteristics behave differently under different climatic conditions. 2017 saw very hot conditions during the lead up to The Championships and particularly throughout week one. These conditions were like those experienced in week one of The 2015 Championships, but very different to the cool, wet Championships of 2016 when rain caused a backlog of matches that led to middle Sunday being used to catch up on the schedule.

The consistency of surface characteristics in recent years is even more impressive when we consider that court surfaces were over 40˚C for much of week one in both 2015 and 2017. The wilting point of perennial ryegrass is approximately 28˚C!

In this heat, the plant is under severe stress. Targeted irrigation is used to allow the plant some degree of recovery, to ensure that live grass cover does not decline too quickly and that baked surfaces do not increase in surface hardness too rapidly.

Like Roger Federerer, surface characteristics on courts in 2017 were as consistent as ever!